Several detachable rotary devices, such as cold pavement planers and rock wheels, are available for attachment to vehicles such as front end loaders, including the Model CP18 Cold Planer available from Alitec Corporation of Brownsburg, Indiana, the AP400 Cold Planer available from DigTec of Columbia, S.C., and the H18 Rock Wheel available from HydraWheel of Austin, Tex. The detachability of these devices from a vehicle has made them very cost effective since many other types of attachments may be mounted on the same vehicle. However, it is often difficult to use a cold planer or rock wheel near a vertical wall or obstruction, such as a curb.
The pavement planing machine disclosed in U.S. Pat. No. 4,878,713 may be attached to a skid-steer front end loader and may be both tilted and laterally shifted. However, the degree to which the housing of the rotary tool, the planer, can be shifted is limited. The planer cannot extend beyond the edges of the vertical supports of the frame of the apparatus. Therefore, it is difficult to use this planing machine to horizontally plane an area where a road surface meets a vertical wall or curb. The planing machine, through its tilting mechanism, may be able to plane near a curb if the vehicle straddles the curb or is positioned on the higher surface. However, it is desireable to keep the vehicle on a level surface, and, in many instances, it is impossible to straddle the curb. Other laterally shiftable planers and digging booms are disclosed in representative U.S. Pat. Nos. 4,262,966, 4,762,371 and 1,916,247. However, the rotary tools of these devices also cannot be laterally shifted beyond the interior edges of the frame. Therefore, it is desireable to provide a detachable rotary apparatus in which the tool is able to extend beyond the frame of the apparatus for these types of operations.
To laterally shift a rotary apparatus, various methods well known in the art may be used to provide power for the shifting. For example, both the tilting and shifting mechanisms in U.S. Pat. No. 4,878,713 are driven by a single hydraulic cylinder; the shifting mechanism disclosed in U.S. Pat. No. 4,262,966 is driven by a separate motor requiring power from a second source not already available from the front end loader; the planar disclosed in U.S. Pat. No. 4,762,371 uses an electric motor or power take-off from the tractor to which it is attached; and the rack and pinion system of the laterally shiftable digging boom disclosed in U.S. Pat. No. 1,916,247 is manually actuated through the use of a hand crank.
Stump grinders often provide a means for shifting a narrow drum beyond the sides of its frame. However, these devices move in a arcuate path rather than a linear lateral path as is preferred for pavement planing. Also, stump grinders generally have a narrow cutting device which is unsuitable for pavement planing.